Capsule-type medical device and medical system

ABSTRACT

A method of transmitting images in a subject to an outside of the subject using a wireless signal is provided. The method including: (a) transmitting to the outside of the subject a first signal corresponding to a first image obtained using a first imaging device; (b) transmitting to the outside of the subject a second signal corresponding to a second image obtained using a second imaging device; and (c) repeating (a) and (b), where at least initiation of the transmitting the first signal and initiation of the transmitting the second signals is alternately performed

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.11/186,587 filed on Jul. 21, 2005, which is a continuation of U.S.application Ser. No. 10/205,513, now U.S. Pat. No. 6,951,536, whichclaims benefit of Japanese Applications Nos. 2001-229952 filed on Jul.30, 2001 and 2001-333125 filed on Oct. 30, 2001, the contents of each ofwhich are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a capsule-type medical device andmedical system for conducting, for example, examinations in somaticcavities with a capsule body incorporating an image pickup device.

2. Description of the Related Art

Capsule-type endoscopes, which are used to conduct, for example,examinations by inserting a capsule body shaped as a capsule intosomatic cavities and lumens of human being or animals have recently beensuggested.

For example, the endoscope disclosed in Japanese Patent ApplicationLaid-open No. H7-111985 comprises a spherical capsule whose shape wassplit in two.

However, within the framework of such conventional technology, the twocapsules were almost of the same size. Therefore, ability of advancingand easiness of swallowing were not sufficiently improved.

Further, endoscopes have recently come into wide use in medical andindustrial fields. For example, in case of endoscopic examinations insomatic cavity, an insertion member has to be inserted and the patient'spain is increased. A conventional example of a capsule-type endoscopeshaped as a capsule to resolve this problem was disclosed in JapanesePatent Application Laid-open No. 2001-95755.

However, because capsule-type endoscopes capture images while executingunidirectional movement in lumen portions in the body by utilizingperistalsis inside the body, in the conventional example, the images ofthe entire inner wall of lumen are difficult to be captured without amiss.

On the other hand, Japanese Patent Application Laid-open No. 2000-342526discloses an endoscope in which illumination and observations means areprovided on the front and back ends of a long cylindrical member.

In this case, observations can be conducted with two observation meanswith different observation directions. Therefore, the drawbacks of theabove-described conventional examples can be overcome or eliminated.However, the problem is that because of a long cylindrical shape, theendoscope is difficult to move smoothly through curved portions and thesignificant patient's pain is increased.

SUMMARY OF THE INVENTION

Accordingly, a capsule-type medical device, which is advanced through adigestive tract of a human being or animal for conducting anexamination, therapy, or treatment is provided. The capsule-type medicaldevice comprising: a plurality of capsule bodies; a soft linking unitwhich links the plurality of capsule bodies and has an outer diameterless than that of any of the capsule bodies; and a joining member whichjoins two or more of the plurality of capsule bodies in a prescribedposition.

Also provided is a method for examination, therapy, or treatment of thedigestive tract of a human being by using a capsule-type medical devicecomprising a plurality of capsule bodies. The method comprising:swallowing the capsule-type medical device in a linear shape; advancingthe capsule-type medical device entirely through the narrow lumenportion of the digestive tract; and joining at least two of theplurality of capsule bodies in the prescribed position at apredetermined portion of the digestive tract.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates the capsule-type endoscopic system of the firstembodiment of the present invention;

FIG. 2 is a sectional view illustrating the structure of thecapsule-type endoscope of the first embodiment;

FIG. 3 illustrates the capsule-type endoscope of the first embodiment,which moves from the stomach into the duodenum;

FIG. 4 illustrates the structure and functions of the illuminationdevice and observation device component of the first embodiment;

FIG. 5 illustrates a part of the structure shown in FIG. 4;

FIG. 6 is a sectional view illustrating the structure of a part of thecapsule-type endoscope which is a modification example of the firstembodiment;

FIG. 7 is a sectional view illustrating the structure of thecapsule-type endoscope of the second embodiment of the presentinvention;

FIG. 8 illustrates the state of examining the inside of a somatic cavitywith the capsule-type endoscope of the second embodiment;

FIG. 9 illustrates the state of recovering the endoscope with a recoverytool when the endoscope is blocked in an isthmus;

FIG. 10 is a sectional view illustrating the first capsule portion inthe modification example of the second embodiment;

FIG. 11 is a perspective view, with a partial cut-out, of the structureof the capsule-type medical device of the third embodiment of thepresent invention;

FIG. 12 is a sectional view illustrating the configuration of the maincomponents of the capsule-type medical device of the first modificationexample of the third embodiment of the present invention;

FIG. 13 illustrates the configuration of the main components of thecapsule-type medical device of the second modification example of thethird embodiment of the present invention;

FIG. 14 illustrates the external appearance of the capsule-typeendoscope of the fourth embodiment of the present invention;

FIG. 15 illustrates the internal structure of one capsule body of thefourth embodiment of the present invention;

FIG. 16A and FIG. 16B explain the operation in the usage state of thecapsule-type endoscope of the fourth embodiment;

FIGS. 17A to 17D illustrate the sequence of operations in conducting theendoscopic examination according to the fourth embodiment;

FIG. 18 is a block-diagram illustrating the configuration of theelectric system of the external unit and display system of the fourthembodiment;

FIG. 19 is a block-diagram illustrating a modification example of theconfiguration of the external unit of the fourth embodiment;

FIGS. 20A to 20F are timing charts of illumination and image capturingconducted when the external unit shown in FIG. 19 was used;

FIG. 21 illustrates a modification example of the antenna configurationof the fourth embodiment;

FIG. 22 is a perspective view illustrating a part of the capsule-typeendoscope of the first modification example of the fourth embodiment;

FIG. 23 illustrates the state in which the cover of capsule-typeendoscope shown in FIG. 22 was removed and the capsule body is installedin a rewriting device;

FIG. 24 illustrates the internal structure of the capsule body shown inFIG. 22;

FIG. 25 illustrates the internal structure of the capsule body in thesecond modification example of the fourth embodiment;

FIG. 26 schematically illustrates the capsule-type endoscope of thefifth embodiment of the present invention;

FIG. 27 schematically illustrates the capsule-type endoscope of thefirst modification example of the fifth embodiment of the presentinvention;

FIG. 28 schematically illustrates the capsule-type endoscope of thesecond modification example of the fifth embodiment of the presentinvention;

FIG. 29 illustrates a part of internal configuration of the capsule-typeendoscope of the sixth embodiment of the present invention;

FIG. 30A and FIG. 30B are timing charts for explaining the operation ofcontrolling the intensity of light emission by an external signal,according to the sixth embodiment of the present invention;

FIG. 31 explains a part of configuration of the capsule-type endoscopeof the seventh embodiment of the present invention;

FIG. 32 illustrates a part of configuration of the capsule-typeendoscope of the modification example of the seventh embodiment of thepresent invention;

FIG. 33 illustrates the structure of the antenna of the external unit ofthe eighth embodiment of the present invention;

FIG. 34 illustrates the structure of the antenna of the firstmodification of the eighth embodiment of the present invention;

FIG. 35 illustrates the structure of the antenna of the secondmodification of the eighth embodiment of the present invention;

FIG. 36A and FIG. 36B explain the structure of the capsule-typeendoscopic system of the ninth embodiment of the present invention;

FIG. 37 illustrates the structure of the capsule-type endoscope of thetenth embodiment of the present invention;

FIG. 38 explains endoscopic examination of the tenth embodiment of thepresent invention;

FIG. 39A and FIG. 39B explain the structure of the capsule-typeendoscope of the first modification of the tenth embodiment of thepresent invention;

FIG. 40A and FIG. 40B explain the structure of the capsule-typeendoscope of the second modification of the tenth embodiment of thepresent invention;

FIG. 41 illustrates the structure of the capsule-type endoscope of thethird modification of the tenth embodiment of the present invention; and

FIG. 42 explains the operation in a state in which two capsule bodies ofthe capsule-type endoscope of the third modification of the tenthembodiment of the present invention are combined.

The above and other objects, features and advantages of the inventionwill become more clearly understood from the following descriptionreferring to the accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The embodiments of the present invention will be explained hereinbelowwith reference to the accompanying drawings.

First Embodiment

FIGS. 1 to 6 illustrate the first embodiment of the present invention.FIG. 1 illustrates the structure of the capsule-type endoscopic systemof the first embodiment. FIG. 2 illustrates the internal structure ofthe capsule-type endoscope of the first embodiment. FIG. 3 illustrate anexample of utilization relating to the movement from the stomach to theduodenum. FIG. 4 illustrates the structure and functions of theillumination device and observation device components. FIG. 5illustrates a part of the structure shown in FIG. 4. FIG. 6 illustratesthe structure of a part of the capsule-type endoscope which is amodification example.

As shown in FIG. 1, a capsule-type endoscopic system 1 of the firstembodiment of the capsule-type medical device of the present inventionis composed of a capsule-type endoscope 3 of the first embodiment, whichis swallowed by a patient 2 and used for examination inside the somaticcavities, an external unit 5 disposed outside the body of patient 2 andequipped with an antenna 4 for wireless reception of image informationpicked up by the capsule-type endoscope 3, and a personal computer(abbreviated as PC hereinbelow) 7 capable of taking in the imagesaccumulated in the external unit 5 and displaying them on a monitor 6 byvirtue of detachable connection of the external unit 5. The PC 7 iscomposed by connecting a keyboard 9 for data input and the monitor 6 toa PC body 8 and is detachably connected to the external unit 5 with anUSB cable 10 or the like.

FIG. 2 illustrates the internal structure of the capsule-type endoscope3 of the first embodiment.

The capsule-type endoscope 3 comprises a first capsule 11 a and a secondcapsule 11 b as two capsule-like hard units of different diameters and asoft flexible tube 12 connecting the capsules and having a diameter lessthan the diameter of the two capsules 11 a, 11 b, and has a structure inwhich the two capsules 11 a, 11 b are connected by the tube.

In the first capsule 11 a, the cylindrical peripheral portion of a hardcapsule frame 13 is water-tight sealed with a dome-like hard transparentcover 15 via a seal member 14, this cover also covering the opening ofcapsule frame 13. An image pickup device and an illumination device arehoused inside the first capsule.

An objective lens 16 constituting the image pickup device (observationdevice) is mounted on a light-shielding lens frame 17 and disposedopposite the transparent cover 15 in the central portion of the internalspace covered with the dome-like transparent cover 15. An image pickupelement, for example, a CMOS image pickup device 18 is disposed in theimage forming position of the objective lens.

Furthermore, for example, white LEDs 19 are disposed as illuminationdevices in a plurality of places around the lens frame 17, and the lightemitted by the white LEDs 19 passes through the transparent cover 15 andilluminates the space outside thereof. Moreover, a drive circuit 20 fordriving and inducing the emission of light by the white LEDs 19 and fordriving the CMOS image pickup device 18, and a controller 21 forcontrolling this drive circuit 20 and provided with a function ofconducting signal processing with respect to the output signals of CMOSimage pickup device 18 are disposed on the rear surface side of CMOSimage pickup device 18. The drive circuit and the controller are securedto the capsule frame 13.

Further, a connection socket 22 for connecting and securing one end oftube 12 is provided in the center of the end surface (back end surface)of capsule frame 13 on the side thereof opposite the transparent cover15. One end of tube 12 is water-tightly connected and secured to theconnection socket.

Moreover, one end of an electric cable 23 which is an electricconnection member advanced the inside of the tube 12 is connected to thecontroller 21, and the other end thereof is connected to the secondcapsule 11 b. The tube 12 is formed from a flexible tube made frompolyurethane, poly(vinyl chloride), silicone, and the like.

The length of tube 12 linking the first capsule 11 a and the secondcapsule 11 b is almost equal to, or greater than the length of thesmaller first capsule 11 a.

The electric cable 23 is curled, laid in a zigzag manner, or spirallywound inside the tube 12 so that practically no tension is applied tothe electric cable 23 even when the shape of tube 12 is changed.

In the second capsule 11 b which is larger in size than the firstcapsule 11 a, the open end side of capsule frame 24, which is a batteryhousing provided with a function of battery housing means, is detachablycovered with a battery housing lid 26, for example, via a seal member 25inserted in the cylindrical surface part thereof. The external part ofthe battery housing lid 26 is covered with an elastic resin cover 28,which serves as a protective cover, to a proximity of a connectionsocket 27 of tube 12 in the capsule frame 24. The elastic resin cover 28can be put on or taken off by using an elastic force thereof.

A battery 29, for example, a button-type battery, atransmission-receiving, circuit 30, and an antenna 31 are enclosed inthe capsule frame 24. The transmission-receiving circuit 30 iselectrically connected to the controller 21, generates the signals whichare to be transmitted, and demodulates the received signals. The antenna31 is connected to the transmission-receiving circuit 30 and sends theimage information picked up by the CMOS image pickup device 18 to theexternal unit 5 or receives control signals radio transmitted from theexternal unit 5.

The battery 29 serving as a power supply is connected so as to supply adrive power to the transmission-receiving circuit 29, controller 21, anddrive circuit 20.

An external thread 32 is provided on the cylindrical side surfaceportion of the second capsule 11 b, and an internal thread for engagingwith the external thread 32 is provided on the inner peripheral surfaceof battery housing lid 26. Furthermore, a circular groove is provided onthe cylindrical side surface portion of the second capsule 11 b, and aseal member 25 for waterproofing, for example, such as an O-ring, ishoused therein, thereby water-tightly sealing the inside of the capsulebetween the seal member and the battery housing lid 26 which is broughtin contact therewith under pressure.

Furthermore, the other end of tube 12 is water-tightly secured, forexample, with an adhesive to the connection socket 27 located in thecentral portion of capsule frame 24 on the side opposite the batteryhousing lid 26.

Moreover, the external unit 5 receives signals from the capsule-typeendoscope 3 with the antenna 4, and the image demodulated by an internalsignal processing circuit (not shown in the figure) is displayed on aliquid-crystal monitor 5 a provided in the external unit 5 and alsocompressed and stored in the internal nonvolatile memory or a small harddisk or the like.

A control member 5 b is provided in the external unit 5. By operatingthe control member 5 b, it is possible to send a control signal in theform of electromagnetic wave from the antenna 4, and if the capsule-typeendoscope 3 receives this control signal, the controller 21 can vary theillumination interval of illumination device and the image capturingperiod of the image pickup device.

For example, the capsule-type endoscope 3 usually conducts one cycle ofillumination and image pickup within 2 seconds, but if control signalsare once received with a short interval, one cycle of illumination andimage pickup is conducted within 1 second. If the control signals with ashort interval are received twice in a row, two cycles of illuminationand image pickup are conducted within 1 second. Furthermore, if a cancelcontrol signal is sent, the capsule-type endoscope 3 returns to theusual illumination and image pickup period.

Furthermore, connecting the external unit 5 to PC 7 upon completion ofendoscopic examination with the capsule-type endoscope 3 makes itpossible to load the image data accumulated by the external unit 5 intothe PC 7 and to display them with the monitor 6.

In the capsule-type endoscope 3 of such a configuration, the twocapsules 11 a, 11 b one of which is smaller than the other are linked bya flexible tube 12, and the image pickup device and illumination deviceare housed in the first capsule 11 a. Furthermore, the battery 29serving as a power supply and the antenna 31 are housed in the largersecond capsule 11 b, electric power is supplied to the image pickupdevice and illumination device via the electric cable 23 is passedthrough the inside of the tube 12, and the image signals picked up bythe image pickup device are transmitted to the outside from the antenna31.

In this case, making one of the capsules 11 a, 11 b smaller than theother facilitates swallowing and makes advancing easier. Furthermore,housing the illumination device and image pickup device on the front endside, namely on the end side opposite to the one connected with the tube12, of the smaller first capsule 11 a and illuminating zones ahead inthe movement direction of capsule-type endoscope 3 allows to pick upimages of the illuminated somatic cavities.

Furthermore, the rear side of the smaller first capsule 11 a is cornercut and a chamfer 34 is provided so as to obtain an inclined orspherical surface. Thus, the periphery of the surface connected to thetube 12 which is a soft part linking the hard units is chamfered toobtain a spherical or inclined shape.

The outer periphery of the front portion of the larger second capsule 11b, which is connected by the tube 12, is also provided with a chamfer 35to obtain an inclined or spherical shape improving the advancingability. The chamfer 35 is made larger than the chamfer 34 on the backend side of the first capsule 11 a to permit unobstructed passage.

Further, the electric cable 23 is made longer than the tube 12 to followthe deformation of flexible tube 12.

The length of tube 12 is equal to or greater than the length of thesmaller first capsule 11 a. Thus, providing a length exceeding the fixedvalue makes it easier to swallow the endoscope. When the length of tube12 is within a range from the length almost equal to that of the smallerfirst capsule 11 a to the length twice that, twisting or knotting of thesoft linking unit is prevented.

In case of endoscopic examination of patient 2 who swallows thecapsule-type endoscope 3 of the above-described embodiment, as shown inFIG. 1, making the two capsules 11 a, 11 b different in size allows themto be smoothly and easily swallowed, when the endoscope is swallowedwith the smaller end forward, and also permits the movement direction tobe controlled, as shown in FIG. 3.

As shown in FIG. 3, when the capsule-type endoscope 3 advances from astomach 36, through a pylorus 37, to a duodenum 38, the smaller firstcapsule 11 a easily enters first, thereby allowing the movementdirection and observation direction to be matched.

The dome-like transparent cover 15 is provided on the front side of thesmaller first capsule 11 a so as to cover the front surface of thiscapsule, and this transparent cover 15 encloses the image pickup deviceand illumination device. The objective lens 16 constituting the imagepickup device is fit into the light-shielding lens frame 17 forshielding the unnecessary light reflected from the inner side of thetransparent cover 15 and protrudes forward beyond the illuminationdevice. Thus, the light-shielding lens frame is provided around theobservation device and the front surface of the light-shielding lensframe projects beyond the front surface of illumination device.

Because of its shape, the capsule-type endoscope 3 conducts illuminationand observation (image pickup) through the dome-like window. In thiscase, the reflection and back reflection of the illuminated light on theinner surface of the dome-like transparent cover 15 provided on thefront surface of illumination device and observation device can occurwith a high probability and the observed image can contain a ghostcomponent or flare. For this reason, the function of the light-shieldinglens frame 17 is of major importance.

In the present embodiment, as shown in FIG. 4, when the height of lensframe 17 is represented by h and the distance between objective lens 16and illuminating device is represented by s, the positional relationshipof lens frame 17 and illumination device is set such as to prevent thelight emitted from the illumination device and then reflected from theinner surface of transparent cover 15, as completely as possible, fromentering the objective lens 16. In other words, the outer diameter andheight of the light-shielding lens frame and the distance between theillumination device and observation device are set such as tosubstantially prevent the incidence of the unnecessary light such as thelight emitted from the illumination device and then reflected from theinner surface of the dome-like observation window onto the observationdevice. For example, a part of the light emitted, as shown by the arrow,from one white LED 19 constituting the illumination device shown in FIG.4 is reflected by the inner surface of transparent cover 15, butpractically all the reflected light is prevented from entering theobjective lens 16 located on the inner side of lens frame 17, therebyensuring the field of view created by the objective lens 16.

Furthermore, the light that passed through the inner surface oftransparent cover 15 and was reflected by the outer surface thereof isalso prevented as completely as possible from entering the objectivelens 16. As a result, random penetration of reflected light issubstantially eliminated and observation performance is improved.

FIG. 5 is an expanded view of the main part of the structure shown inFIG. 4, which illustrates the effective illumination of the view fieldrange.

As shown in FIG. 5, the range of field of view with respect to theobservation object 39, which is defined by the objective lens 16installed in the lens frame 17 disposed in the center, can beilluminated with white LEDs 19 serving as illumination devices anddisposed on both sides of the range of field of view. Here, for the sakeof simplicity, the objective optical system is represented by acombination of objective lens 16 and lens frame 17.

In the figure:

x: distance from the front surface of the objective optical system tothe observation object 39,

h: height of objective optical system (from the end surface of the whiteLED 19),

d: diameter of the objective optical system,

θ: view angle of the objective optical system,

s: distance between the objective optical system and white LED 19,

a: radius of field of view,

b: illumination range.

As shown in FIG. 5, a and b are set such that a≦b. As a result, therange of field of view can be effectively illuminated, without shieldingthe illumination light with the objective optical system.

Here,a=d/2+x tan θb=(x/h)·(s−d/s)−d/2.

The operation of the present embodiment will be described below.

When somatic cavities of the patient 2 are examined with thecapsule-type endoscope 3, the battery 29 has to be housed as shown inFIG. 2. In this case, the portion where the battery 29 is housed can bedetached by unscrewing. If the elastic resin cover 28 is removed and thebattery housing lid 26 is removed by unscrewing, then a new battery 29can be housed in an easy manner.

When the capsule-type endoscope 3 is to be used, the patient 2 or doctorinstalls the battery 29 and screws the battery housing lid 26 into thecapsule frame 24, which is one part of the split battery housing unit,that is, assembles the battery housing unit, thereby turning the powersupply ON and initiating the capturing of images or transmission andreceiving of signals. The power supply can be thus turned ON in an easymanner, and no special switch is required. Conversely, when thecapsule-type medical device is discarded, the battery can be easilyremoved, which is beneficial for the environment.

Further, in the present embodiment, the battery 29 is placed in thesecond capsule 11 b. Therefore, if it is broken, problems can beassociated with electric discharge or leakage. To prevent the breakage,the capsule is protected with the elastic resin cover 28. Further,water-tight sealing with the seal member 25 such as an O-ring isimplemented to prevent water and other body fluids from penetrating intothe space where the battery 29 is housed.

As shown in FIG. 1, the patient 2 can smoothly swallow the medicalcapsule 3 by inserting it into the mouth the first capsule 11 a sidefirst, this first capsule having a small outer diameter.

The capsule-type endoscope 3 conducts illumination and image pickup witha constant cycle, and the picked-up image information is wirelesstransmitted from the antenna 31. The image information is received bythe external unit 5 and displayed on the liquid-crystal monitor 5 a orstored.

Therefore, the endoscopic examination crew can monitor the informationwith the liquid-crystal monitor 5 a. Further, since the outer diameterof the first capsule 11 a is less than that of the second capsule 11 band the first capsule 11 a advances easier than the second capsule 11 b,the first capsule 11 a readily becomes ahead in the movement direction.In other words, when the endoscope advances from the stomach 36, throughthe pylorus 37, to the duodenum 38, as shown in FIG. 3, it easilyadvances to the deep zones smaller first capsule 11 a first.

Furthermore, in this case since the illumination and image pickupdevices are provided on the distal end of the first capsule 11 a, theimage of somatic cavities in the movement direction can be picked up andimages, which can be easily diagnosed in the same manner as diagnosticimages obtained with the usual endoscope, can be also obtained.

In another modification example, the below-described image pickup devicemay be used instead of the CMOS image pickup device.

The image pickup device used herein employs a threshold voltagemodulation image sensor (VMIS), which is the next-generation imagesensor, possessing the merits of both the above-described CMOS imagepickup device and the CCD (charge coupled device). The structure of thissensor is entirely different from that of the conventional CMOS sensorin which the light receiving unit is composed of 3-5 transistors andphotodiodes. Thus, the VMIS has a structure employing a technology ofmodulating the threshold value of a MOS transistor with a chargegenerated by the received light and outputting the changes of thethreshold value as the image signals.

Such an image sensor features a combination of high quality of CCD and ahigh degree of integration and low power consumption of CMOS sensor.

For this reason, it was employed in the disposable capsule-typeendoscopes. Using such a feature makes it possible to realize adisposable endoscope (soft or hard) or a low-price endoscope. Thevoltage modulation image sensor (VMIS) can be used not only in suchendoscopes, but also in usual videoscopes. In addition, such voltagemodulation image sensor (VMIS) has the below-described excellentfeatures.

The structure is simple, with one transistor per one image sensor.

The VMIS has excellent photoelectric characteristic such as highsensitivity and high dynamic range.

Since the sensor can be fabricated by a CMOS process, a high degree ofintegration and low cost can be realized.

There are sensors of a variety of types, such as QCIF (QSIF) size, CIF(SIF) size, VGA type, SVGA type, XGA type, and the like. In thecapsule-type endoscope with wireless communication of the presentinvention, small sensors of “QCIF (QSIF) size” and “CIF (SIF) size” areespecially preferred from the standpoint of wireless transmission speed,power consumption, and because they are easy to swallow.

FIG. 6 illustrates a modification example of the first embodiment andshows part of the first capsule 11 a of this modification example.

In this modification example, a water-tight seal 40 is additionallyimplemented in white LEDs 19, objective lens 16, and lens frame 17located inside the transparent cover 15 in the first capsule 11 a shownin FIG. 2. In other words, a structure is employed in which theillumination device and observation device ensure water tightness forthe hard unit with no dome-like observation window attached. Thus, thetransparent cover 15 has a water-tight structure inside thereof on thefront side, but even when cracks appear in the transparent cover 15 andit loses the waterproofing function thereof, using the water-tight seal40 provides a water-tight structure for the entire surface facing thetransparent cover 15 inside the transparent cover 15 so as to ensureelectric insulation preventing the permeation of water into the electricsystem, such as the internal drive circuit 20. The side surface portionis sealed with the seal member 14 in the same manner as shown in FIG. 2.

With such a structure no water permeates into the electric systemlocated inside the transparent cover 15 and electric insulationproperties can be maintained even when cracks appear in the cover and itloses the waterproofing function thereof.

The present embodiment has the following effects.

Swallowing is facilitated by splitting one capsule in two to decreasethe size thereof and making one of the resulting capsules less than theother. In other words, easiness of swallowing can be improved.Furthermore, changing the size of the capsules readily matches themovement direction with the observation direction. In other words, theobservation ability can be improved.

Further, adjusting the arrangement of the objective optical system andalso the illumination and transparent cover 15 reduces randompenetration of reflected light. In other words, the observation abilitycan be improved.

Moreover, the power supply ON/OFF and battery replacement can beconducted in an easy manner. The endoscope is easy to handle andenvironment-friendly.

Since waterproofing of inner circuits is maintained even when cracksappear in the transparent cover, accidents are prevented.

In another modification example of the present embodiment, the frontsurface of the objective lens 16 of the lens frame 17 may be brought incontact with the inner surface of the transparent cover 15. In thiscase, the transparent cover 15 has high resistance to deformation evenwhen a large external force is applied thereto.

In other words, since the objective lens 16 or lens frame 17 is arrangedso as to be in contact with the transparent cover 15, the transparentcover 15 is not deformable nor rupturable and, therefore, the strengthcan be increased.

Second Embodiment

The second embodiment of the present invention will be describedhereinbelow with reference to FIGS. 7 to 10.

FIG. 7 is a sectional view illustrating a capsule-type endoscope 2B ofthe second embodiment of the present invention. This capsule-typeendoscope 2B comprises three capsules 41 a, 41 b, 41 c and flexibletubes 42 a and 42 b linking the adjacent capsules 41 a, 41 b and theadjacent capsules 41 b, 41 c.

In this case, the first capsule 41 a and third capsule 41 c disposed onboth ends have almost the same outer diameter, whereas the secondcapsule 41 b disposed in the center with respect thereto has a largerouter diameter.

Furthermore, the first capsule 41 a and third capsule 41 c have astructure similar to that of the first capsule 11 a of the firstembodiment, and the second capsule 41 b has a structure similar to thatof the second capsule 11 b.

In the first capsule 41 a, a cylindrical permanent magnet 43 a isprovided to surround the cylindrical peripheral portion of a capsuleframe 13 a and the opening of capsule frame 13 a is covered with adome-like transparent cover 15 a. The circumferential part of thisopening is water-tightly fixed with a waterproofing adhesive 44 a, andan image pickup device and an illumination device are housed insidethereof. A ferroelectric substance producing a strong magnetic force maybe used instead of the permanent magnet 43 a.

An objective lens 16 a constituting the image pickup device (observationdevice) is mounted on a light-shielding lens frame 17 a and disposedopposite the transparent cover 15 a in the central portion of theinternal space covered with the dome-like transparent cover 15 a. Animage pickup element, for example, a CMOS image pickup device 18 a isdisposed in the image forming position of the objective lens. Forexample, the objective lens 16 a is disposed so that the outer surfacethereof is in contact with the inner surface of transparent cover 15 a.

Furthermore, for example, white LEDs 19 a are disposed as illuminationdevices in a plurality of places around the lens frame 17 a, and thelight emitted by the white LED 19 a passes through the transparent cover15 a and illuminates the space outside thereof.

Moreover, a drive circuit 20 a for driving and inducing the emission oflight by the white LEDs 19 a and for driving the CMOS image pickupdevice 18 a, and a controller 21 a for controlling this drive circuit 20a and provided with a function of conducting signal processing withrespect to the output signals of CMOS image pickup device 18 a aredisposed on the rear surface side of CMOS image pickup device 18 a. Thedrive circuit and the controller are secured to the capsule frame 13 a.

As shown in FIG. 6, a water-tight seal 40 a is implemented on the innerside of the transparent cover 15 a, and the electric system such as thedrive circuit 20 a and the like can be maintained in an electricallyinsulated state by the water-tight seal 40 a even when cracks appear inthe transparent cover 15 a and water tightness provided by the portionscovered with the transparent cover 15 a is lost.

Further, a connection socket 22 a for connecting and securing one end ofa tube 42 a is provided in the center of the end surface of capsuleframe 13 a on the side thereof opposite the transparent cover 15 a. Oneend of the tube 42 a is water-tightly connected and secured to theconnection socket.

Moreover, one end of an electric cable 23 a which is passed through theinside of the tube 42 a via the opening of a disk-like latch 45 a isconnected to the controller 21 a, and the other end thereof is connectedto the second capsule 41 b.

The latch 45 a is connected to a latch 47 a of the second capsule 41 bvia a linking metallic wire 46 a inserted into the tube 42 a andprovides free bendability for the flexible tube 42 a, so as to preventdisrupting the linkage between capsules 41 a and 41 b.

An electric cable 23 a is, for example, wound around the linkingmetallic wire 46 a and inserted into the tube 42 a. A chamfer 34 a isformed on the rear peripheral portion of the first capsule 41 a bycutting it at an angle or corner cutting so as to obtain a sphericalshape.

The third capsule 41 c has a similar structure. The components assignedwith the reference symbol (a) that were explained in describing thefirst capsule 41 a are now assigned with the reference symbol (c) andthe explanation thereof is omitted.

In the second capsule 41 b which is larger in size than the first andthird capsules 41 a, 41 c, a seal member 25 is inserted, for example,into the cylindrical side surface of a capsule frame 24 serving asbattery housing means and the end side thereof which is opened towardthe third capsule 41 c is detachably covered with a battery housing lid48.

Connection sockets 27 a, 27 c for connecting and securing the tubes 42a, 42 b are provided in the center of respective end surfaces of thecapsule frame 24 and the battery housing lid 48, and the tubes 42 a, 42b are water-tightly connected and fixed, for example, with awaterproofing adhesive.

Further, the outer peripheral portions of the batteries housing the lid48 and the capsule frame 24 are covered with an elastic resin cover 49up to the vicinity of connection sockets 27 a, 27 c.

The capsule frame 24 encloses, for example, a button-type battery 29, atransmission-receiving circuit 30, and an antenna 31. Thetransmission-receiving circuit 30 is electrically connected tocontrollers 21 a, 21 c, generates signals to be transmitted, anddemodulates the received signals. The antenna 31 is connected to thetransmission-receiving circuit 30 and sends the image informationcaptured by the CMOS image pickup devices 18 a, 18 c to the externalunit (not shown in the figure) or receives control signals wirelesstransmitted from the external unit.

The battery 29 is connected so as to supply drive electric power to thetransmission-receiving circuit 30, controllers 21 a, 21 c, and drivecircuits 20 a, 20 c.

An external thread 32 is provided on the cylindrical side surface of thesecond capsule 41 b, and an internal thread, which is to be engaged withthe external thread 32, is provided on the inner peripheral surface ofthe battery housing lid 48. Further, a circumferential groove isprovided on the cylindrical side surface of the second capsule 41 b anda seal member 25 such as an O-ring is housed therein, therebywater-tightly sealing the inside of the capsule between the seal memberand the battery housing lid 48 which is brought in contact therewithunder pressure.

In the capsule-type endoscope 2B of such a structure, three capsules 41a, 41 b, 41 c obtained by splitting into three portions are linked bythe flexible tubes 42 a, 42 b. In this case, both end capsules 41 a, 41c are of almost the same size, and the central capsule 41 b is largerthan the two end capsules 41 a, 41 c.

The two end capsules 41 a, 41 c are provided with an illuminationdevice, image pickup device, drive circuits used for illumination andimage pickup devices, and a processing circuit for the image pickupdevice. The central capsule 41 b is provided with the battery 29,transmission-receiving circuit 30, and antenna 31, and various functionsof the two end capsules 41 a, 41 c commonly use the battery 29 andtransmission-receiving circuit 30 of the central capsule.

Further, exchange of electric power and signals between the threecapsules 41 a, 41 b, 41 c is conducted by electric cables 23 a, 23 clocated inside the flexible tubes 42 a, 42 b. Linking metal wires 46 a,46 b are passed through the inside of the tubes 42 a, 42 b so that thetubes 42 a, 42 b can be freely bent without disrupting the connection ofcapsules 41 a, 41 b and 41 b, 41 c.

Further, chamfers 35 a, 35 b larger than the above-described chamfers 34a, 34 c are formed in the elastic resin cover 49, which serves as aprotective cover, in the corner portion facing the first capsule 41 aand the corner portion facing the third capsule 41 c, respectively.

The operation of this embodiment will be described below.

Since the size of the two end capsules 41 a, 41 c is smaller than thatof the central capsule 41 b, any of the two end capsules moves first ina somatic cavity 50, as shown in FIG. 8. Therefore, zones ahead andbehind in the movement direction can be observed with the two endcapsules 41 a, 41 c, each being provided with the illumination and imagepickup devices. When the endoscope moves leftward, as shown in FIG. 8,the capsule 41 a illuminates the zone ahead and picks up the imagestherefrom, and the capsule 41 c illuminates the zone behind and picks upthe images therefrom. The reverse is the case when the endoscope movesrightward.

In the present embodiment, cylindrical permanent magnets 43 a, 43 c ormagnetic substance is provided in both end capsules 41 a, 41 c. As shownin FIG. 9, the permanent magnets 43 a, 43 c or magnetic substance makesit possible to recover the endoscope easily with a recovery tool 55provided with a permanent magnet 54 at a front end of a cord-like member53 when the capsule-type endoscope 2B is stuck and cannot advancethrough an isthmus 51 in the somatic cavity 50 and has to be recovered.

In other words, when the front end of the recovery tool 55 is broughtclose to the capsule-type endoscope 2B, the permanent magnet 54 isattracted to the permanent magnet 43 a or 43 c due to a magnetic forceacting between the permanent magnet 54 at the front end of recovery tool55 and the permanent magnet 43 a or 43 c at the capsule-type endoscope2B. The capsule-type endoscope 2B can be then easily pulled out, thatis, recovered by pulling out the recovery tool 55.

The above explanation is related to the recovery operation, but thepermanent magnets 43 a, 43 c or magnetic substance can be also used forremotely controlling the position or orientation of the capsule-typeendoscope 2B inside a somatic cavity by an external magnetic field.

The effect of the present embodiment will be described below.

Of the three above-described hard units, the outer diameter or length ofthe two end hard units is smaller than that of the hard unit other thanthe two end units. In particular, splitting a capsule in three decreasesthe size of capsule body and makes it easy to swallow the capsule. Thus,easiness of swallowing can be improved. In this case, swallowing can bemade even more easier by decreasing the size of the capsules 41 a, 41 clocated on both sides of central capsule 41 b. The outer diameters orlengths of the two end hard units are almost the same.

Since the illumination devices and image pickup devices are provided incapsules 41 a, 41 c at the both sides, the observation direction can bethe same as the movement direction and zones ahead and behind in themovement direction can be observed at the same time. Therefore,observation performance is improved. Further, since the size of capsules41 a, 41 c located on both sides of the central capsule 41 b isdecreased, movement is facilitated.

Further, since the power supply function and signal transmission andreceiving function are made common for a plurality of illuminationdevices and image pickup devices, the number of components can bedecreased, which is beneficial for size reduction. In other words, sizecan be reduced and easiness of swallowing can be improved. The functionof control unit may be also made common.

Further, providing the cylindrical permanent bodies 43 a, 43 c ormagnetic substance allows the recovery or magnetic guidance. Therecovery is facilitated and operability is improved.

FIG. 10 illustrates a part of the first capsule 41 a as a modificationexample of the present embodiment.

One end of a linking metal wire 46 a located inside the tube 42 aconnecting the capsules 41 a, 41 b, on the side of capsule 41 a, asshown in FIG. 10, has a slidable latch structure.

Thus, a latch 45 a located inside the capsule 41 a is disposed so thatit is free to slide forward and backward inside a tubular body (ring) 56a disposed between the rear surface of controller 21 a and the innersurface of capsule frame 13 a.

Further, in the present embodiment, a lens frame 17 a is abutted withthe inner surface of the transparent cover 15 a.

The resulting effect is that the transparent cover 15 a is reinforcedand the resistance thereof to external forces is improved.

Further, in the present embodiment, the linking metal wires 46 a, 46 clocated inside the tubes 42 a, 42 c connecting the three capsules wereseparate from electric cables 23 a, 23 c, but in a structure of yetanother modification example, the electric cables 23 a, 23 c may alsoserve as the linking metal wires 46 a, 46 c.

The resulting effect is that the structure can be simplified.

A structure may be also used in which one end of the linking metal wireis made slidable, as shown in FIG. 10, and the electric cables 23 a, 23c also serve as the linking metal wires 46 a, 46 c. In this case, asliding latch 45 a may be provided with an electric contact andelectrically connected to the controller 21 a via the tubular body 56 a.

In yet another modification example, a VMIS may be used instated of theCMOS image pickup device.

Third Embodiment

The third embodiment of the present invention will be described belowwith reference to FIGS. 11 to 13. FIG. 11 illustrates a capsule-typemedical device 2C which is the third embodiment of the presentinvention. Structural components identical to those of the firstembodiment are assigned with the same reference symbols and theexplanation thereof is omitted.

The capsule-type medical device 2C has a structure in which a variety ofsensor means 61 such as a pH sensor, optical sensor, temperature sensor,pressure sensor, blood sensor (hemoglobin sensor), and the like areprovided, for example, as in the first capsule 11 a, for example, in thecapsule-type endoscope 2 of the first embodiment.

Various sensor means 61 are secured to the outer member of the capsule,such as the transparent cover 15, so that sensing zone of sensor means61 is exposed to the outside and the inside of the capsule is maintainedin a water-tight state. Otherwise, the structure is the same as in thefirst embodiment.

Data such as chemical parameters (pH value) of body fluids, brightnessinside a somatic cavity, temperature of various organs, pressure appliedby the inner surface of somatic cavities to the outer surface of thecapsule when the capsule advances therethrough, amount of hemoglobin invarious organs (presence of hemorrhage) are obtained from the sensingzones. The data obtained are temporarily accumulated in a memory (notshown in the figures) located inside the capsule and then transmitted bythe transmission-receiving circuit 30 and antenna 31 to a receiver suchas the external unit 5 located outside the body. By comparing the dataobtained by the receiver with the standard values, the medical crew,such a doctor or nurse, can externally establish the presence ofabnormalities, such as disease or hemorrhage, and to determine thecapsule advancing position or state.

In particular, diagnostics of gastroenterological diseases orphysiological analysis can be conducted with high efficiency bypainlessly establishing the pH value of hemoglobin level in digestiveorgans of the living body with the capsule-type medical device 2C.Highly efficient examination can be conducted by providing a pluralityof sensors according to the object of examination.

FIG. 12 illustrates a part of the capsule-type medical device 2D whichis a modification example of the third embodiment. In the presentembodiment, an ultrasound probe 71 is additionally provided in thesecond capsule 11 b of the first embodiment. In this case, for example,a battery housing lid 26 is formed with a material transmittingultrasound waves, a sealed space is formed in the battery housing lid26, a rotary-type ultrasound oscillator 72 is housed inside this space,and the area around the oscillator is filled with a transfer medium 73.

The ultrasound oscillator 72 is rotated by a motor 74. The elastic resincover 28 of the external surface of the capsule around the ultrasoundoscillator 72 functions as an acoustic lens of ultrasound oscillator 72.The battery housing lid 26 is detachably secured to a capsule frame 24with a screw 76.

The ultrasound oscillator 72 makes possible the ultrasound tomographyinside the somatic cavities, driving and signal processing beingconducted by the control circuit 75. Data obtained are transmitted tothe external receiver in the same manner as described above. As aresult, diagnostics of the presence of abnormalities in the depthdirection of deep portions of somatic cavities such as a small intestinecan be conducted. If a structure is used with observation devices onboth sides, then diagnostics of both the surface and deep portions insomatic cavities can be conducted. An ultrasound probe with anelectronic scanning system rather than mechanical scanning system may bealso used.

FIG. 13 illustrates a capsule-type medical device 2E of the secondmodification example. This capsule-type medical device 2E is providedwith treatment-therapy means.

In the capsule-type medical device 2E, a medicine compartment 81 and abody fluid compartment 82 are provided, for example, in the elasticresin cover 28 in the second capsule 11 b, for example, in thecapsule-type endoscope 2 of the first embodiment.

The medicine compartment 81 and body fluid compartment 82 have openingsthat are open on the outer surface of the capsule, and the openings arecovered with soluble membranes 83, 84 composed of fatty acid membranesor the like that are digested by the liquid present in intestines or ofgelatin consumed by gastric juice. A medicine 85 for treatment isenclosed in the medicine compartment 81. Once the capsule-type medicaldevice 2E has arrived to the target location, the soluble membrane 83 isdissolved, the opening is opened, and the medicine 85 is directlyadministered. At the same time, body fluid can be sucked into the bodyfluid compartment 82.

Further, a linear actuator 88 for driving a syringe 87 so that it can beprotruded is provided, for example, inside a part of transparent cover15 in the first capsule 11 a, this syringe having a compartment 86accommodating a hemostatic drug.

Thus, once a hemorrhaging zone has been established by a blood sensor orobservation device, usually a procedure can be employed by which thesyringe 87 for injecting the hemostatic drug accommodated inside thecapsule is projected in response to a signal from the external unit 5located outside the body and a powdered drug or ethanol which is thehemostatic drug located inside the compartment 86 is sprayed over thehemorrhaging zone to stop bleeding.

Embodiments composed by partially combining the above-describedembodiments are also covered by the present invention.

As described above, in accordance with the present invention, acapsule-type medical device which is advanced the inside of the somaticcavities and lumens of human being or animals for conductingexamination, therapy, or treatment comprises at least two hard units anda soft linking unit which links the aforesaid plurality of the hardunits and has a diameter less than that of any of the hard units,wherein one of the plurality of hard units is different in size fromother hard units. Therefore, when the smaller hard unit is swallowedfirst, the medical device can be easily swallowed and the smaller unitcan easily be advanced the inside of the lumens.

Fourth Embodiment

FIGS. 14 to 21 illustrate the first embodiment of the present invention.FIG. 14 shows the external appearance of the capsule-type endoscope ofthe fourth embodiment. FIG. 15 shows the internal structure of one ofthe capsule bodies. FIGS. 16A and 16B explain the operation in a stateof usage. FIGS. 17A, 17B, 17C, and 17D illustrate the endoscopicexamination procedure. FIG. 18 is a block-diagram illustrating thestructure of electric systems of the external unit and display system.FIG. 19 is a block-diagram illustrating the structure of the externalunit, which is a modification example of the fourth embodiment. FIGS.20A to 20F are timing charts illustrating timing diagrams ofillumination and image pickup in the embodiment employing the externalunit shown in FIG. 19. FIG. 21 illustrates an example of antennastructure in another modification example of the fourth embodiment.

As shown in FIG. 14, a capsule-type endoscope 101 of the fourthembodiment of the present invention is composed of a capsule-shapedfirst capsule body 102A and a second capsule body 102B, each containingan image pickup device, and a soft thin strap 103 connecting back endsides of the two capsule bodies 102A, 102B.

In the present embodiment, the first capsule 102A and the second capsule102B have the same structure. As an example, FIG. 15 shows the innerstructure of the second capsule 102B.

In the second capsule 102B the front surface side of the body that hasan almost cylindrical shape and is semi-spherically closed on the backend side thereof is covered with a semi-spherical transparent cover 105b.

An objective lens 106 b is mounted in the center of the front surfaceportion of a body 104 b inside the transparent cover 105 b, and a CMOSimage pickup device 107 b serving as a solid-state image pickup elementis disposed in the image forming position of the lens.

A plurality of LEDs 108 b generating, for example, a white light aredisposed around the objective lens 106 b. LEDs 108 b are driven by a LEDdrive circuit 109 b provided inside the body 104 b.

The image of the examinee located inside a somatic cavity andilluminated by the LEDs 108 b is formed by the objective lens 106 b onthe CMOS image pickup device 107 b serving as an image pickup elementand disposed in the image forming position of the lens. This image isphotoelectrically converted by the CMOS image pickup device 107 b. TheCMOS image pickup device 107 b is driven by the drive signals from adriving and processing circuit 111 b, conducts signal processing byextraction and compression of image signal components with respect tophotoelectrically converter output signals, and sends the signals to atransmission circuit 112 b.

The transmission circuit 112 b conducts high-frequency modulation of theinput image signals, converts them into high-frequency signals, forexample, with a frequency of 2.4 GHz, and emits electromagnetic wavesfrom an antenna 113 b to the outside. Power necessary for an operationof the transmission circuit 112 b, driving and processing circuit 111 b,and LED drive circuit 109 b is supplied from a battery 114 b.

Structural components of capsule body 102A corresponding to structuralcomponents of capsule body 102B explained with reference to FIG. 15 willbe explained below by using reference symbols (a) instead of referencesymbols (b). Furthermore, structural components identical to thoseexplained in FIG. 15 are shown, for example, in FIG. 24.

In the present modification, transmission from a transmission circuit112 a of capsule body 102A and transmission circuit 112 b of capsulebody 102B is conducted by slightly changing the transmission frequency.The signals are received by an external unit 116 (see FIG. 17A) disposedoutside.

In other words, electromagnetic waves transmitted by antennas 113 a and113 b connected to the transmission circuit 112 a of the capsule body102A and transmission circuit 112 b of the capsule body 102B,respectively, are received by the external unit 116 shown in FIG. 17A.

FIG. 17A shows how a patient 117 swallows the capsule 101 when theendoscopic examination is begun. In this case, since the picked-up imagesignals are transmitted by the capsule-type endoscope 101 aselectromagnetic waves, those electromagnetic waves are received by theexternal unit 116 mounted, for example, with a belt of the patient 117at a waist line of the patient 117 and stored in the memory locatedinside the external unit 116.

When the endoscopic examination with the capsule-type endoscope 101 iscompleted, the external unit 116 is installed in a data capture unit 119provided in a display system 118 shown in FIG. 17B, and the image dataaccumulated in the external unit 116 can be imported in the displaysystem 118 via the data capture unit 119.

FIG. 18 shows the configuration of the electric systems of the externalunit 116 and display system 118.

The external unit 116 serving as a receiver comprises two antennas 121a, 121 b receiving with good efficiency the electromagnetic waves of thefrequency transmitted by the antennas 113 a, 113 b of the capsule bodies102A and 102B, and the high-frequency signals induced in the antennas121 a, 121 b are input in respective receiving circuits 122 a, 122 b.

The receiving circuits 122 a, 122 b are controlled by respective controlcircuits 123 a, 123 b, and the control circuits 123 a, 123 b demodulatethe high-frequency signals received by the receiving circuits 122 a, 122b and conduct control so that those signals are successively stored in amemory 124.

The memory 124 is composed of a hard disk (abbreviated as HDD in thefigure). The memory 124 is connected to a connector 125. When theexternal unit 116 is installed in the data capture unit 119 shown inFIG. 17B, a connector 125 is connected to a connector 126 of datacapture unit 119, as shown in FIG. 18.

The connector 126 is connected to a memory 130 of display system 118.The memory 130 is controlled by a control circuit 131. The image data ofobserved images that are accumulated in the memory 124 of external unit116 are developed and processed by an image processing circuit 132 viathe memory 130 and stored, that is, recorded in a memory 133 which is arecording unit.

The memory 133 is, for example, composed of a hard disk. The memory 133is connected to a display circuit 134 conducting display processing, andimage signals sent to the display circuit 134 are displayed by a displayunit 136 conducting display of images as captured images via acomparison circuit 135 conducting comparison. The comparison circuit 135is connected to a disease image database (abbreviated as DB) 137,compares the images from the disease image database 137 with thecaptured image, retrieves a similar past disease image, andsimultaneously displays it on the display unit 136 as the DB image.

Furthermore, the control circuit 131 is connected to a console 138 suchas a keyboard, and the command to capture images, to input patient data,to input diagnostic results, and the like are conducted from the console138.

A specific feature of this embodiment, as shown in FIG. 14, is that theback ends of the two capsule bodies 102A, 102B, which are opposite tothe front ends covered with transparent covers 105 a, 105 b areconnected with a flexible strap 103 that has a width sufficiently lessthan that of the outer diameter of those capsule bodies 102A, 102B andsuch a structure allows for illumination and image pickup in mutuallyopposite directions.

The operation relating to this embodiment will be described below.

When endoscopic examination is conducted, the external unit 116 isattached to the waste of the patient 117, for example, as shown in FIG.17A, and the patient 117 is asked to swallow the capsule-type endoscope101.

The capsule-type endoscope 101, for example, after the preset time,conducts illumination and image pickup, the picked-up image signals aretransmitted from the antenna 113 a, 113 b, and the external unit 116receives the transmitted image signals and stores them in the memory124.

FIGS. 16A and 16B show how the images of the inside, for example, of alarge intestine 140 are picked up with the capsule-type endoscope 101.

In the present embodiment, the two capsule bodies 102A, 102B areconnected by the thin flexible strap 103. Therefore, even whenexamination is conducted inside a lumen, for example, a right coloncurve, as shown in FIG. 16A, the endoscope can be freely bent in strap103. Therefore, the endoscope can smoothly advance the inside of thelumen, similarly to a single-capsule-type endoscope. Therefore,examination can be conducted without causing paint or discomfort to thepatient 117.

Furthermore, in the present embodiment, the capsule bodies 102A, 102Bhave a structure such that the sides opposite to the back ends linked bythe strap 103 serve as illumination and image pickup sides. Therefore,for example, as shown in FIG. 16A, there may be instances when a portion140 shown by dotting becomes a dead zone whose image cannot be picked upby the capsule body 102B, which is located in the zone ahead in themovement direction, due to half-moon folds. However, following thisstate, as shown in FIG. 16B, illumination and image pickup with theillumination and image pickup devices of the other capsule 102A isconducted from the direction opposite to that of the preceding capsule102B, and the image of the zone that was a dead zone for the precedingcapsule can be picked up with the succeeding capsule 102A.

Thus, with the present embodiment, the occurrence of portions becomingthe dead zones is prevented to a greater degree than with a singlecapsule body and effective images can be obtained.

Image signals obtained from two capsule bodies 102A, 102B areaccumulated in the memory 124 of the external unit 116, and after thecapsule-type endoscope 101 is discharged to the outside of body, theexternal unit 116 is installed in the data capture unit 119 shown inFIG. 17B and the command signal of image capture is input from theconsole 138 of the display system 118.

In such a case, the image data accumulated in the memory 124 of theexternal unit 116 are transferred into the image processing circuit 132via the memory 130 functioning as a buffer, subjected to processing suchas development, and accumulated one by one as image data in memory 133.

The image data stored in the memory 133 can be successively displayed onthe display device 136 if a display command is input from the console138 by an operator.

Furthermore, when a command input was made to pick up the image similarto the disease image that was accumulated in the disease database 137with respect to the captured image, the image that was captured by thecapsule-type endoscope 101 is displayed together with the disease imagefrom the disease database 137 on the display surface of display device136, as shown in FIG. 17C. In this state, the control circuit 131 shownin FIG. 18 conducts a comparative processing such as pattern matching ofthe captured image and the disease image read out from the diseasedatabase 137 with the comparison circuit 135 and makes a decision as towhether there is a similarity exceeding the preset ratio. If a decisionis made that there is a similarity exceeding the preset ratio, thisimage together with several adjacent images are linked to the data ofdisease database 137 and stored in the memory 133.

Then, only the images that can be related to a disease are extractedfrom all of the captured images and stored, for example, in an imageextraction folder of the memory 133.

As shown in FIG. 17D, the operator then conducts command input from theconsole 138 so as to display the extracted image on the display device136. As a result, the images stored in the image extraction folder aredisplayed successively and the operator can conduct final diagnosticswith good efficiency. Thus, using the database to assist the diagnosticsallows the diagnostics to be half automated and makes possible asignificant reduction of time spent by the doctor on examination.

With the present embodiment, the illumination devices and image pickupdevices are provided in both capsules. Therefore, the observationdirection can be the same as the movement direction and observations canbe simultaneously conducted ahead and behind in the movement direction.As a result, the endoscope can be moved more smoothly inside curvedlumens in a body than in the conventional examples and images can bepicked up without causing strong pain in the patient, and from differentdirections, more specifically, from the movement direction and thedirection opposite thereto. Therefore, high-quality images can beobtained and the number of occurring dead zones is small. Furthermore, aset of images captured inside the body can be obtained and, thus, theoperator saves such a time of picking up images while inserting theendoscope.

FIG. 19 illustrates the structure of a modification example of theexternal unit 116.

The external unit 116 shown in FIG. 18 comprised the two antennas 121 a,121 b, receiving circuits 122 a, 122 b, and control circuits 123 a, 123b. In the present modification example, the external unit comprisessingle antenna 121, a receiving circuit 122, and a control circuit 123.

Further, in the present modification example, as shown in FIGS. 20A to20F, the timings at which the transmission circuits 112 a, 112 btransmit the images obtained by illumination and image pickup by twocapsule bodies 102A, 102B are shifted by half a period (T/2) withrespect to each other to avoid overlapping thereof.

In other words, when the power supply of the two capsule bodies 102A,102B is turned ON and they are set into the operation state, forexample, a LED 108 a of the capsule body 102A is ignited for a shorttime (for example, 1/30 sec) and an image is picked up by the CMOS imagepickup device 107 a and transmitted by the transmission circuit 112 a(almost within half a period, T/2).

Once the transmission by the transmission circuit 112 a has beencompleted, the LED 108 b of the other capsule body 102B is ignited for ashort timer an image is picked up by the CMOS image pickup device 107 band transmitted by the transmission circuit 112 b. Once the transmissionby the transmission circuit 112 b has been completed, the LED 108 a ofthe first capsule body 102A is again ignited.

With such an operation, the image signals transmitted by thetransmission circuits 112 a, 112 b are received by one antenna 121,received by the receiving circuit 122, and stored in the memory 124.

In this case, when the transmission frequencies of the transmissioncircuits 112 a and 112 b are slightly different, they can be receivedwith a sufficiently good efficiency by the same antenna 121.Furthermore, based on the transmission frequency, the external unit 124can decide which of the image pickup elements has picked up the image.

Further, when the transmission circuits 112 a and 112 b transmit at thesame frequency, transmission may be conducted as shown in FIGS. 20A to20F. In this case, the transmission may be conducted by adding anidentification code, for example, to the header of the image which is tobe transmitted.

In this case, the identification code may be recognized by the externalunit 116 and separated from the image data, followed by storage in thememory 124, or the image data may be stored in the memory 124, with theidentification code attached thereto, and the identification code may berecognized and separated from the image data in the display system 118.

FIG. 21 shows an antenna of the modification example of external unit116. In the present modification example, the external unit 116installed in a belt is connected with a connection cable 142 to anecktie-type antenna row 144 located on a shirt 143 that is worn by thepatient 117. This necktie-type antenna row 144 is detachably secured tothe shirt 143 with a button 145.

The necktie-type antenna row 144 thus hangs down from the neck of thepatient 117, and the antenna of the most intensive electromagnetic wavereceived among a plurality of antennas 144 a constituting the antennarow 144 is used.

With the present modification example, the installation can be conductedin an easy manner, without intensifying the pressure on the patient 117.Further, a plurality of antennas 144 a are arranged in the verticaldirection and located in the vicinity of the center in the widthdirection of the body of patient 117. Therefore, as the capsule-typeendoscope 101 descends by peristalsis, since a plurality of antennas 144a are present along this direction, signals can be effectively receivedby the closest antenna 144 a.

The first modification example of the present embodiment will bedescribed below with reference to FIG. 22.

In the capsule-type endoscope 101B of modification example shown in FIG.22, the external portion of the capsule body 102A shown in FIG. 14 canbe removed as a cover 146. An electrode 148 of a communication port 147is exposed in the back end of a capsule body 102A′ from which the cover146 has been removed.

As shown in FIG. 23, the back end of the capsule body 102A′ from whichthe cover 146 has been removed is installed in a connector socket 149 aof a rewriting unit 149, and the operation program located inside thecapsule body 102A′ can be changed by manipulating the input keys 150 ofthe rewriting unit 149.

FIG. 24 illustrates the rewriting unit 149 and the internal structure ofthe capsule body 102A′ in this case, that is, when the cover 146 hasbeen removed. In the fourth embodiment, the capsule body 102A′additionally comprises a timing control circuit for conducting timingcontrol or a timing (abbreviated as TG in FIG. 22 and elsewhere)generator 151 and the above-mentioned communication port 147 connectedto the timing generator 151.

A CPU 152 conducting control operation and a memory 153 such as a flashmemory having written therein a program determining the controloperation of the CPU 152 are provided inside the timing generator 151,and the contents of programs thereof can be rewritten by connecting tothe rewriting unit 149. The other capsule body 102B has the samestructure.

The operation is described below.

Prior to using the endoscope for endoscopic examination, the cover 146is removed and the capsule body 102A′ is set into the rewriting unit149, as shown in FIG. 23. Then, input keys 150 are manipulated and therewriting unit 149 sends data such as driving timing of illumination andimage pickup or illumination period to the timing generator 151 ofcapsule body 102A′ via the communication port 147.

The CPU 152 of timing generator 151 rewrites the data in memory 153 withthe transmitted data. Thus, the CPU 152 serving as a setting unit canrandomly set from the outside the settings required for the realizationof functions in at least one of the illumination device, observationdevice, wireless transmission unit, and control unit.

The capsule body 102A′ is thereafter disconnected from the rewritingunit 149, and the cover 146 is attached. Further, the same operation isconducted with respect to the other capsule body 102B′. The patient 117is then asked to swallow the capsule-type endoscope 101B.

Illumination and image pickup are then conducted at the illumination anddevice timing set by manipulating the input keys 150.

As a specific example of data that are written, for example, when mainlythe large intestine of the patient 117 is examined, the settings aremade such that one frame image is picked up in 2 seconds within 6 hoursafter the capsule-type endoscope 101B was swallowed and two frame imagesare picked up in 1 second after the 6 hours have elapsed.

In such a modification example, a frame rate can be increased to conductdetail observation, for example, in the zone where the patient'ssymptoms are suspicious, so as to obtain a large number of images in thezone which requires careful examination based on the patient's symptoms.In other words, the operator can freely set the image pickup conditionsaccording to the zone which is to be examined, thus, effective picked-upimages can be obtained, and the consumption of battery energy can bereduced.

FIG. 25 shows a capsule body 102A″ of the second modification example.In the structure of this capsule body 102A″, a drive and processingcircuit 111 a shown in FIG. 24 is connected to a memory 154 a and thememory 154 a is connected to a communication port 147 a.

Data on the patient which is to be examined can be input into the memory154 a by the rewriting unit 149 prior to endoscopic examination.

Furthermore, image data picked up by the driving and processing circuit111 a are accumulated in the memory 154 a during endoscopic examination.Once the endoscope capsule has been recovered, the image dataaccumulated in the memory 154 a are read out together with the patient'sdata by a display system provided with a communication port connectableto the communication port 147 a. As a result, the image data can bemanaged in a state in which the relationship thereof with the patient'sdata is maintained.

In the first modification example shown in FIG. 24, a memory storing thepatients data may be also provided, and when the image data aretransmitted, the patient's data stored in the memory may be initiallytransmitted as header information of the image data.

Fifth Embodiment

The fifth embodiment of the present invention will be described belowwith reference to FIGS. 26 to 28. FIG. 26 shows a capsule-type endoscope101C of the fifth embodiment. In the capsule-type endoscope 101C, forexample, the objective lenses 106 a, 106 b of capsule bodies 102A, 102Bof the fourth embodiment are replaced with an objective lens 107 a′ witha standard angle of view and an objective lens 107 b′ with a wide angleof view. For sake of simplicity, only the objective lens 107 a′ andobjective lens 107 b′ are shown in FIG. 26. The same is true for FIG. 27described hereinbelow.

In this case, an angle of view providing for an observation field ofview from 120° to 140° is set as a standard angle of view, and an angleof view providing for an observation field of view from 160° to 180° isset as the wide angle of view.

Further, the movement direction in case of endoscopic examination withthe capsule-type endoscope 101C is such that the images are first pickedup with the objective lens 107 a′ with the standard angle of view.Otherwise the structure is identical to that of the fourth embodiment.The observation devices of each hard unit have objective optical systemswith mutually different angles of field of view.

With the present embodiment, overlooking can be reduced by conductingfar-point observations with the objective lens 107 a′ with a standardangle of view in the capsule body 102A located ahead zone in themovement direction and conducting near-point observations with theobjective lens 107 b′ with a wide angle of view in the rear capsule body102B.

FIG. 27 shows a capsule-type endoscope 101D of the first modificationexample. In this capsule-type endoscope 101D, the devices conductingillumination and image pickup in the direct-viewing direction of capsulebodies 102A, 102B in the fourth embodiment are modified so as to conductillumination and image pickup in the directions inclined to the movementdirection of capsule-type endoscope 101D.

In case of the structure shown in FIG. 27, the fields of view ofobjective lenses 107 a″, 107 b″ are defined by directions inclined inthe mutually opposite directions with respect to the movement directionof capsule-type endoscope 101D. For example, if the field of view ofobjective lens 107 a″ is inclined downward, then the field of view ofthe other objective lens 107 b″ is inclined upward.

With the present modification example, since the inclined viewingdirections are different ahead and behind the endoscope, the lumens canbe observed within a wider range by combining the images obtained withboth lenses.

FIG. 28 shows a capsule-type endoscope 101E of the second modificationexample. This capsule-type endoscope 101E has a structure in which threecapsule bodies 156A, 156B, and 156C are linked by a thin flexible strap57. Further, the capsule 156A has an objective lens 158 a with a fieldof view in the direct-viewing direction, the capsule body 156B has anobjective lens 158 b with a field of view in the downward side-viewingdirection, and the capsule 156C has an objective lens 158 c with a fieldof view in the upward side-viewing direction.

With this modification example, the inside of lumens can be observedwithin even wider range by combining the images obtained with all of thecapsule bodies.

Sixth Embodiment

The sixth embodiment of the present invention will be describedhereinbelow with reference to FIG. 29, FIG. 30A, and FIG. 30B. FIG. 29shows a capsule-type endoscope 101F of the sixth embodiment. In thecapsule-type endoscope 101F, a toggle switch 161 and a chargeaccumulation circuit 162 are provided as the LED drive circuit 109 a inthe capsule-type endoscopes 102A′ and 102B′, for example, in thecapsule-type endoscope 101B shown in FIG. 22. Only one capsule body 102Ais shown in FIG. 29.

Further, a transmission-receiving circuit 112 a′ is employed instead ofthe transmission circuit 112 a. If a switch operation signal Sk is sentfrom the outside, it is received by the antenna 113 a, demodulated bythe transmission-receiving circuit 112 a′, and sent to a CPU 152 a oftiming generator 151 a. The CPU 152 a conducts control operationaccording to the switch operation signal Sk.

More specifically, the LED 108 a, as shown in FIG. 30A and FIG. 30B,intermittently emits light under the effect of electric power of battery114 a. However, if the switch operation signal Sk is received, the CPU152 a of timing generator 151 a switches the toggle switch 161 a so thatit is connected to the charge accumulation circuit 162 a. As a result,the electric power accumulated in the charge accumulation circuit 162 ais supplied to the LED 108 a and a large quantity of light is emitted.

With the present embodiment, for example, when the capsule-typeendoscope 101F reaches the position which apparently requires carefulexamination, transmitting the switch operation signal Sk from theoutside makes it possible to cause the emission of a large quantity oflight by the LED 108 a and to obtain a bright image with a good S/Nratio.

More specifically, even when the LED 108 a is caused by the battery 114a to emit light inside the esophagus or small intestine, a sufficientlybright image can be obtained. However, inside the stomach or largeintestine, the illumination light is not fully received and dark imagesare sometimes obtained.

If a switch operation signal Sk is sent from the outside with respect tothe zones for which dark images are obtained, for example, zones thatare apparently the affected areas, then the entire electric power thatwas charged into the charge accumulation circuit 162 within thesufficient period of time is supplied via the toggle switch 161 as alarge electric current into the LED 108 a, and a large quantity of lightis emitted instantaneously. As a result, a bright image, even if stillimage, with a good S/N ratio can be obtained in the desired zones insidethe stomach and large intestines.

Further, since the LED 108 a generates heat, illumination in usualobservations is conducted at an electric current of no higher than astandard value. However, the LED 108 a practically does not degrade evenif a large electric current such as reaching the standard value ispassed instantaneously therethrough.

In the present embodiment, the amount of illumination light was switchedby the switch operation signal Sk. However, a configuration may be alsoused in which the illumination and image pickup periods can be changedby the switch operation signal, that is, the operation periods of aplurality of illumination devices and observation devices can be changedby the switch operation signal from the outside.

Seventh Embodiment

The seventh embodiment of the present invention will be described belowwith reference to FIG. 31 and FIG. 32. FIG. 31 shows a capsule-typeendoscope 101G of the seventh embodiment. In this capsule-type endoscope101G, a dip switch 164 a is provided instead of the communication port147 a shown in FIG. 22 and the transmission frequency of the internaltransmission circuit can be variably set by the dip switch 164 a.

With this embodiment, even if a plurality of capsule-type endoscopes101G are swallowed, setting different frequencies for the transmissionof image signals by each endoscope makes it possible to recognize andmanage the signals during receiving.

FIG. 32 shows a capsule-type endoscope 101H of the modification exampleof the seventh embodiment. In this capsule-type endoscope 101H, aninfrared radiation (IR) port 167 a is provided on the inner side of atransparent cover glass 166 a provided on the external surface in thecapsule body 102A, for example, shown in FIG. 29.

The communication is conducted with infrared radiation and the IR port168 provided in the rewriting unit 149. Further, in this modificationexample, the cover 146 is not separated. With this modification example,setting of illumination and image pickup timing can be conducted evenwithout connecting to the rewriting device 149. Thus, the CPU conductsthose settings by using remote communication such as infrared radiationcommunication and the like. Otherwise, the effect obtained is almostidentical to that explained with reference to FIG. 29.

Eighth Embodiment

The eighth embodiment of the present invention will be describedhereinbelow with reference to FIGS. 33 to 35. FIG. 33 shows a structurerelating to the antenna of external unit 116. In this embodiment, astripe-like antenna row 172 is attached to the front button 171 portionof a shirt 143 of the patient 117. A plurality of antennas 172 aconstituting the antenna row 172 are connected to the external unit 116with a connection cable 142.

The operation and effect of this embodiment are almost identical tothose explained with reference to FIG. 21.

FIG. 34 shows the first modification example of the eighth embodiment.In FIG. 34, a shirt 174 incorporates the antenna row. Buttons 175 alsofunction as antennas.

FIG. 35 shows the second modification example of the eighth embodiment.In FIG. 35, an apron-like antenna row 176 is in the form of an apron puton the shirt 143. A plurality of antennas 176 a are provided in theapron-like antenna row 176. The operation and effect of this embodimentare almost identical to those explained with reference to FIG. 33.

Ninth Embodiment

The ninth embodiment of the present invention will be describedhereinbelow with reference to FIGS. 36A and 36B. FIGS. 36A and 36Billustrate a state of endoscopic examination of the ninth embodiment.FIG. 36A relates to the initial stage of examination. FIG. 36Billustrates how the images obtained in the course of the examination aretransmitted from the patient's home to the hospital.

In this embodiment, the data capture unit 119, for example, installed inthe external unit 116 is connected to a connection unit 183 of atelephone line 182 connected to a telephone 181, and further connectedto the display system 118 disposed in a hospital 184 via the telephoneline 182.

Otherwise, the configuration is identical to that of the fourthembodiment.

As for the operation of this embodiment, when endoscopic examination isconducted, as shown in FIG. 36A, the patient 117 swallows thecapsule-type endoscope 101.

Image data obtained with capsule-type endoscope 101 are accumulated inthe external unit 116. Upon completion of the endoscopic examination,the external unit 116 is connected to the data capture unit 119connected to the telephone line 182 and the image data are automaticallytransferred to the hospital or other remote site via the telephone line182.

In the hospital, the image data are received and automatically imported.The final diagnostics is conducted by the doctor.

In this embodiment, diagnostics is possible even when the patient is ina remote location far from a hospital. Furthermore, since theexamination of the patient can be conducted not only in a hospital, thedegree of freedom of patient 117 is increased.

Further, the transmission of image data is not limited to that via thetelephone line and wireless transmission may be also conducted.Moreover, the transmission may be conducted with other communicationsmeans such as cellular phones, internet, and the like.

Tenth Embodiment

The tenth embodiment of the present invention will be describedhereinbelow with reference to FIGS. 37 to 42. In this embodiment,illumination and image-pickup functions are separated between aplurality of capsule bodies, and illumination and image pickup areconducted by combining the operations of the capsule bodies. In acapsule-type endoscope 185 of the tenth embodiment shown in FIG. 37, acapsule body 186A and capsule body 186B are connected with a strap 187.

Further, a LED 188 emitting white light, a LED drive circuit 189, and abattery 190 are enclosed in the capsule body 186A. An objective lens191, a CMOS image pickup device 192, a drive and processing circuit 193,a transmission circuit 194, and an antenna (not shown in the figure) areenclosed in the other capsule body 186B. The capsule bodies 186A, 186Bare connected with a signal line 195.

Magnets 196 a, 196 b are provided inside the capsule bodies 186A, 186B,respectively. As shown in FIG. 38, the capsule bodies can be easilyattracted to each other by magnetic forces of magnets 196 a, 196 bserving as joining components. Therefore, the two capsules are joined inthe prescribed position.

FIG. 38 illustrates the operation of the present embodiment. Whenendoscopic examination of the patient 117 is conducted, the patient isasked to swallow the capsule-type endoscope 185 straightened out into aline.

When the endoscope passes through a narrow lumen portion of an esophagus197, the endoscope advances to a deeper region, while maintaining thelinear shape. If it then reaches a wide zone, such as a stomach 198, thetwo capsule bodies 186R, 186B are drawn close to each other by themagnetic forces of the magnets 196 a, 196 b.

Illumination and image pickup (including the function of transmittingthe image signals) are then conducted in such a state. At least one ofthe capsule bodies is provided with a magnetic sensor, such as a Hallelement, for detecting the state in which the capsule bodies arecombined by magnetic forces of the magnets 196 a, 196 b, and the controlinitiating the illumination and image pickup based on the detectionoutput of the sensor is conducted by a control unit (not shown in thefigures). Alternatively, as shown in FIG. 24, illumination and imagepickup may be conducted after the prescribed time has elapsed, or asshown in FIG. 29, the operation control may be conducted based on theexternal signals.

With the present embodiment, image signals can be can be obtained byimproving the illumination and image pickup functions executed by thecapsule bodies. For example, high-resolution images with good S/N ratiocan be obtained by increasing the quantity of illumination light orincreasing the number of pixels in the image pickup element.

FIGS. 39A and 39B show a capsule-type endoscope 185′ of the firstmodification example. The magnets 196 a, 196 b are not used in thecapsule-type endoscope 185′ and a strap 187′ formed from a shape memorymaterial is employed as the strap 187 serving as a joining member.

In this case, the strap 187′ formed from a shape memory material wassubjected to shape memory processing such that it has a linear shape atroom temperature, as shown in FIG. 39A, but is bent, as shown in FIG.39B, if the temperature becomes no less than the body temperature,thereby combining the two capsule bodies 186A, 186B. In this case, too,the operation and effect are almost identical to those explained withreference to FIG. 37.

FIGS. 40A and 40B show a capsule-type endoscope 185″ of the secondmodification example. In the capsule-type endoscope 185″, a strap 187″is formed from a spring material processed (impelled) so as to be bentand to combine the two capsule bodies 186A, 186B, as shown in FIG. 40A.When the endoscope is swallowed, the strap is straightened out, as shownin FIG. 40B. In this case, too, the operation and effect are almostidentical to those explained with reference to FIG. 37.

FIG. 41 shows a capsule-type endoscope 201 of the third modificationexample. In this modification example, combining the capsules improvesthe illumination and image pickup function, more specifically, the imagepickup range, over those obtained when the capsules are not combined.

In the capsule-type endoscope 201, three capsule bodies 202A, 202B, 202Care linked with a thin soft strap 203. The capsule body 202A and othercapsule bodies are hard and have a hard length shown in the figure.

The objective lenses 204 a, 204 c with a field of image view inclinedupward are enclosed in transparent covers in the respective capsulebodies 202A, 202C on both end sides, and image pickup elements 205 a,205 c are disposed in image forming positions of respective lenses. Theimage pickup elements 205 a, 205 c are driven and signals therefrom areprocessed by the image element drive and processing circuits 206 a, 206c.

Further, LEDs 207 a, 207 c for illumination are disposed around theobjective lenses 204 a, 204 c, respectively. The LEDs 207 a, 207 c aredriven by an LED drive circuit 208 provided in the central capsule body202B.

Further, signals that were processed by the image element drive and theprocessing circuits 206 a, 206 c are sent to a transmission circuit 209provided in the central capsule body 202B and are transmitted to theoutside from an antenna (not shown in the figure). A battery 210 is alsoenclosed in the capsule body 202B. Energy such as electric current issupplied to the observation devices such as the image pickup elements205 a, 205 c enclosed in the capsule bodies 202A and 202C by the battery210.

Magnets 211 a, 211 c are provided inside the capsule bodies 202A, 202Con both end sides.

Therefore, similarly to the case explained with reference to FIG. 38, ifthe capsule-type endoscope 201 reaches a wide portion such as a stomach,the capsule bodies 202A, 202C located on both end sides are attractedand combined by the magnets 211 a, 211 c, as shown in FIG. 42.Therefore, the two capsules are joined in the prescribed position.

In such a state, image pickup is possible within a wide range because ofrespective inclined fields of view. The operation and effect in thiscase are similar to those explained with reference to FIG. 37.

The present invention also covers embodiments composed, for example, bypartial combinations of the above-described embodiments.

Having described the preferred embodiments of the invention referring tothe accompanying drawings, it should be understood that the presentinvention is not limited to those precise embodiments and variouschanges and modifications thereof could be made by one skilled in theart without departing from the spirit or scope of the invention asdefined in the appended claims.

1. A capsule type medical device comprising: a) a first imaging deviceadapted to capture a first image of a subject; b) a second imagingdevice adapted to capture a second image of the subject; c) atransmission circuit for transmitting the first and second images usinga wireless signal; and d) wherein the transmission circuit is adapted toalternately perform at least initiation of transmitting a first signaland initiation of transmitting a second signal, the first and secondsignals respectively corresponding to the first and second images. 2.The capsule type medical device according to claim 1, wherein thetransmission circuit transmits the first and second signals such thatthe transmission of the first signal does not overlap with thetransmission of the second signal.
 3. The capsule type medical deviceaccording to claim 1, wherein the transmission circuit is adapted totransmit one of the first and second signals after completion oftransmission of the other of the first and second signals.
 4. Thecapsule type medical device according to claim 3, wherein the firstimaging device includes a first illumination device and the secondimaging device includes a second illumination device; and the secondillumination device is adapted to illuminate the subject after thetransmission of the first signal by the transmission circuit iscompleted.
 5. The capsule type medical device according to claim 3,wherein the first imaging device and the second imaging device arearranged so as to have a different direction of view with respect toeach other.
 6. A method of transmitting images in a subject to anoutside of the subject using a wireless signal, comprising: a) (a)transmitting to the outside of the subject a first signal correspondingto a first image obtained using a first imaging device; b) (b)transmitting to the outside of the subject a second signal correspondingto a second image obtained using a second imaging device; and c) (c)repeating (a) and (b), wherein at least initiation of the transmittingthe first signal and initiation of the transmitting the second signalsis alternately performed.
 7. The method according to claim 6, whereinthe transmitting of the first and second signals is performed such thatthe transmitting the second signal does not overlap with thetransmitting the first signal.
 8. The method according to claim 6,wherein transmission of one of the first and second signals is performedafter the transmission of the other of the first and second signals. 9.The method according to claim 6, further comprising adding anidentification code to the signal capable of identifying at least one ofthe first imaging device and the second imaging device.
 10. The methodaccording to claim 9, wherein adding the identification code includesadding the identification code to a header of the signal.
 11. The methodaccording to claim 8, wherein the first imaging device captures thefirst image in a first direction; and the second imaging device capturesthe second image in a second direction different from the firstdirection.
 12. The method according to claim 6, further comprisingadding an information capable of identifying a patient to the signal.